Resilient bushing and method of making the same



Jly 5, 1938. F. M, GUY 2,122,339

RESILIENT BUSHING AND MTHOD OF MAKING THE SAME I Filed oct.-15. 193e gag!! AWORNEYs.

Patented UNITED STATES .PATENT OFFICE zazzrsss RESILIENT' BUSHING AND METHOD 0F MAKING SAME Frederick IH. Gly I Detroit, Mich., assigner to' Guy and Marton, Incorporated, Detroit, Mich.,

av corporation of Michigan Application umher-15,1936, sel-ln No. niacin s claims. (c1. ca -149.5I

The present-invention relates to resilient bushings and the method of making the same. l Prior to the present invention resilient bushings have been suggested in which an inner core y is connected with an outer shell through the medium of an intermediate layer of a resilient material, such as rubber. In one known method of forming such bushings the resilient member is compressed between the core and the shell 9 either by expansion ofthe core o r by contraction of the shell,l or both, with such force that a ment betw'en the resilient member and the core being in a state of initial tension or in astate in which neither tension nor compression forces are present in the rubber. In all such known bushings the bushing provides a greater resistance to rotativev movements betweeny the core andthe shell than it does to end wise'movements between the core and the shell so that while such bushings may be used for connecting members where it is desired to resist yieldingly the relative. rotative movement between the members.

' Y such members do not have al suilicient resistance to fendwise movements to permit satisfactory use in certain installations, suchfor example as spring shackle connections, particularly those uaed-y with transverse springs, shock -absorber connections, and the like 4or similar uses.

One of theobjects of the present invention,

v therefore, is toprovide a resilient bushing which is adapted to permit relative movement of the' connected members radially and axially through a body of compressed resilient. material, while'l locking the connected` members against displacement dueto endwise movements thereof.'y

Another object of the invention is'to provide a resilient bushing of the type in which a core anda 'shell are resiliently connected through a compressedl and deformed mass of resilient, materlal locked between'the'core and the shell in a manner permitting axial movements of the' core and shell and 'in which provision is made .for

controlling the locking of the parte and the resilient mass to provide a sufiicient volume of resilient material to 'resist yieldingly the forces tending to displace said core and shell.

Another object of the invention is to provide a resilientbushing which is adapted to permit yielding movement between the core'and the shell by working of the resilient element without substantial friction losses due to slippage between the resilient element and the core or shell.

Another object of the invention is to provide a novel resilient connector in which considerable relative movements of the connected members are permitted but only a relatively small amount ofresllient material is used in the connector.

A further object ofthe invention is to provide a resilient connector wherein resilient resistance to endwise movement of the connected parts is provided.

A still further object of the invention is to provide a resilient connector made in the form of a bushing compressedon a shaft or a stud, l by a swaged shell, wherein excessive axial movement between the shaft and the shell is limited `and possible endwise separation of the connected members is prevented.

Anadded object of the invention is 'to provide a novel resilient connector of the foregoing character which is durable in use. simple in construction and economical to manufacture.

Other objects and advantages of this invention will appear in the following description and appended claims, reference being had to the` accompanying drawing forming a part of this specification, wherein three embodiments of the present invention are illustrated.

In the drawing. wherein like reference char.- acters designate corresponding parts in the severalviews, I

Fig. i is'a side'elevation showing a resilient bushing of the present invention as utilized in a shockabsorber connection with a part oi' a chassis of a motor vehicle; Y v

Fig. 2 is alongitudinal sectional view of a resilient bushing of the present invention, the Vsec'- `tion being taken substantially on the line 2--2 of Fig. l;

Flgf`3 illustrates a step in assembling novel y connector;

Fig. 4 illustrates the step vsucceeding the step shown in Fig. 3 in assembling the connector;

Fig.y 5 illustrates a iinal 'step in lassembling the connector in accordance with the invention;

Fig.6 is a longitudinal sectional view of av other modincation of the invention.

Before explaining in detail the pres-ent invention itis to beunderstood that the invention is not lmited inits application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein be- 1 other structures, such for example as in steering rod knuckle, joints, spring shackles, and the like. Referring to Fig. 1 the structure illustrated p therein comprises a shock'absorber of the telescopic type, having an upper snubber Ill and a lower snubber I |,telescopically arranged with respect to each other. On the ends of each of said snubbers there are provided eyelets I2 and I3 adapted to receive the studs lI4 and I5 carried by a bracket I6 secured to the vehicle frame I1 and to the axle I8 supported by a leaf spring I9- tion 24, and a threaded shank 25. Said stud I4 is pressed into a hole 26 provided in the bracket I6, engaging the same by its knurled portion 24, whereby rotation of the stud with respect to said bracketY |6 is prevented. A nut 21 and a lock washer 28 ar'e provi-ded a't the threaded shank 25 which. when' tightened up, secure the stud |4 to the bracket I6 by drawing the shoulder 23 against said bracket I6. The eyelet. I2 of the upper telescopic member I0 is bored to receive a cylindrical shell 29 surrounding the. rubber bushing 20. Said shell 29 is provided with a circular V-shaped rolled bead 30 projecting toward the axis of the stud I4. 'I'he stud I4 is, in turn, provided with a groove 3| concentric with respect to said bead 30 and lying substantially in the same plane therewith. i

The shell 29 is swaged or reduced on the rubber bushing 20, whereby the rubber of the bushing is put in compression in a radial direction,

' which it is believed results in shortening of the radial fibers and an axial stretching of the bushi118, so that the rubbercompletely iills the Y ing is swaged on a smooth cylindrical surface by a smooth shell as is the case in prior structures, the connection thus effected does not afford suiiicient resistance to end thrust between the connected parts. This is due to a variety of factors, and particularly to thefact that the rubber bers have different stresses indierent directions, and the further fact that the rounded bulging ends of the rubber in the bushing causes the bushing to roll on the shaft longitudinally, this rolling being restricted only by decreased resilient resistance of the bushing. In some specic instances, particularly with short thick bushings, the bushing assumes the shape of a ring of subtantially oval cross section and the stud can roll out onl such rubber bushing when subjected to high end thrust loads. Making the bushing thin and long operates to destroy the amount of resiliency ordinarily required. By providing the locking means exemplified in the present embodiment by the bead and groove, I increase the longitudinal resistance ofv the bushing by inducing compression and shearing stresses in therubber mass of the bushing when the connector is' subjected to an end thrust.

Figs. 3, 4 and 5 illustrate the method of assembling the connector shown in Fig. 2. An initial step in the method employed comprises arranging a comparatively narrow and thick rubber ring a on the stud I4. The Vouter shell is next placed around the rubber ring 20d and is swaged or reduced thereon in any suitable manner, such as with the aid of a rotary swaging machine. In the course of this operation the rubber ring 20a assumes the positionillustrated in Fig. 4. The last operations consistin forming the rolled bead on the shell 20, preferably with the aid of a rolling machine indicated diagrammatically by the rollers 50 and 5| (Fig. 5). One of the advantages of the structure shown in Fig. 2 and of the method described above results from the fact that the above operations can be performed land the connector assembledbefore mounting of the shock absorber or other part on the chassis. If desired, the completed connector assembly can bepressed into an eye of theshock absorber and peened thereon or otherwise secured thereto before connecting the shock absorber on the chassis.

Fig. 6 illustrates a modified form of a connector utilizing a bushing of the present invention, wherein the stud 33 is formed with a hollow body portion having a`raised bead 34 provided thereon. In this instance a groove 35 is provided on the outer shell 36. In assembling this structure, a thick narrow rubber ring similar to the ring 20a is placed on the stud 33 and the outer shell' 36 having a preformed groove 35 is swaged thereon. An expansion member is next placed on the inside of the stud 33 and the stud is expanded so as to form the bead 34. 'I'his forces the rubber bushing into the space between the lbead 34 and the groove 35 and formsv a resilient lock between the shell 36 and the stud 33. If desired, the shell 36 may be dispensed with. and vthe groove 35 may be formed on a formed bored surface of the part to whichzthe bushing is to be attached. With this arrangement the stud 33 is expanded outwardly in addition to forming the bead 34, thus compressing the rubber between the stud and the part to which the bushing is to be attached. Thus, in this type of construction the connector and the shock absorber may be locked together as an assembly before they are attached to the vehicle.v

In the modified structure s own in Fig.(7, the

areassc I stud is composed of two sections, namely, a taover the rubber by axial movement thereon. The

resulting positions of the shell and the bushing are indicated in` Fig. '7 in dotted lines. 'I'he angle of taper of the shell li indicated by the letter A, may vary, 15 being a preferredangle for the structure illustrated, The sleeve 38 is `next put in place and locked on the core 31, as mentioned.

Finally, the shell 39 is swaged or reduced to the shape shown in Fig. 7 in solid lines. Thus a completed assembly is produced which can be pressed into the respective eyelet of the shock absorber, or other device in which the bushing is to be utilized. This structure as far as locking of the core and shell with the resilient member is concerned, possesses advantages similar to those described for the preferred structure.

While vulcanized rubber is at\the present time the preferred material from which to form the resilient element of this bushing, it is to be understood that various types of such material may be used, `as well as substitutes therefor, and; I do not desire to be limited to the use of any particular type of resilient materials.

Thus considered from one of its broader as-V pects, my invention contemplates providing a novel resilient connector including a radially compressed resilient bushing, said bushing being provided with locking meansadapted to provide a cushioned locking connection to preventendwise displacement of the -connected parts and an increased resiliency of the bushing to axial thrust loads. The bushing of the present invention likewise permits yielding resilient movements between the parts when subjected to forces tending to cause endwise movement thereof. I

A resilient bushing of the present invention may be utilized in a number of mechanical devices which, by way of example but not of limitation, may include in addition to the foregoing uses, the following: Universal joints employing resilient connections between a carrier member and a driving and drivenshaft, flexible couplings in which the drive is transmitted from the driving shaft to the driven shaft through an interposed resilient bushing, linkage connections of various kinds as used in link belts, pivoting arms,

and the like, clutches employing resilient clutch centers, resilient connections between linkage members employed on braking systems in motor andthe yotherpartbeingconnectediauthecos'asndtlm yielding movement being permitted by fiexure or working occurring. within the resilient mass providing the yielding connection between the core and the shell. The foregoing, as well as other. uses to which the bushing may be'adapted, l are Ato be considered as included within the scope of the appended claims.

I claim:

1. In a method of making a resilient connector having a stud composed of a core and a sleeve fitted thereon, said core and said sleeve adapted, when fitted together, to form a stud containing a groove therein, an outer shell, and a resilient member arranged between such stud and said shell; the steps of arranging the resilient member on the core, placing the tapered outer shell.

thereon, fitting said Sleeve at the thinner end of said core and locking it thereon by swaging the outer end of the sleeve into a locking recess near the outer extremity of the thinner portion of said core, and thereafter swagingthe outer shell on said resilient member into a shape substantiallyparallel to the longitudinal axis of said stud and thereby locking the resilient member betweenfsaid studand said shell.

2. A resilient coupling comprising a two-piece' stud, said stud consisting of a core having shank and shoulder portions near one end thereof and sharply tapering into an extending portion of decreased but substantially uniform diameter on the opposite end therefrom, and a sleeve` tted substantially completely over the said extending portion and compressed into a groove provided on the end of said portion, said sleeve being of substantially, the same diameter as the said core and having an end portion sharply tapering in an opposite direction from the taper of the core, .whereby the stud is created, said stud being of substantially uniform diameter but containing an annular concentric groove between the said tapering portions of the core and sleeve parts thereof a concentric shell arranged around said stud, a raised bead on the inside surface of said shell, arranged to correspond with' the groove formed on said stud and a rubber bushing radially compressed between said stud and said shell and locked in position between said bead and groove.

3. A resilient coupling comprising a two-piece stud, said stud consisting of a core having shank and shoulder portions near4 one end thereof and sharply tapering into an extending portion of decreased but substantially uniform diameter on the oppositebend therefrom, said extending portion having a tapering recess near the end thereof, and a sleeve tted substantially completely over the said extending portion and locked into the said recess, said sleeve being of substsantially the same diameter as the core and having ar. end portion sharply tapering in an opposite direction from the taper of the core, whereby the stud is created, said stud-being of substantially uniform diameter but containing an annular concentric groove between the said tapering portions` of the core and sleeve parts thereof; a concentric shell arranged around said stud, a raised bead .on the inside surface of said fshell, arranged to correspond with the groove formed on said stud and a rubber bushing radially compressed between said stud and said shell and locked in position between said Abead and FRmERICK M. GUY. 

